Mechlabs XX-MOD HPA Drop-In Engine Color:Black Yellow floating valve made from

Yellow floating valve made from high strength 3D printed nylon

Tridos TDC 2

Perfect Airsoft is here for you

The discs to change the exit hole size is a smart idea

It's easy to install and made of a solid material that will last a long time

Mechlabs XX-MOD HPA Drop-In Engine Color:Black Yellow floating valve made fromThe new XMOD engine from Mechlabs is here! Turn your AEG M4 into a modern highspeed HPA marker with this drop in kit. This engine is ready for install into a variety of AEG M4 bodies. The X MOD engine is a fully mechanical HPA engine, that completely replaces the original AEG Gearbox. Featuring both semi auto and full auto, this HPA engine is sure to work for everyone. The triggerpull is amazing and feels like a high end AEG with crisp triggerbreak.